Introduction About Occurrence of Metals:
Metals occur in nature in free as well as combined form. Metals having low reactivity show little affinity for air, moisture, carbon dioxide or other non-metals present in nature. Such metals may remain in elemental or native (free) state in nature. Such metals are called “noble metals” as they show the least chemical reactivity. For example gold, silver, mercury and platinum occur in free state (Watch Occurrence of Metals Video to learn more).
Occurrence of Metals:
On the other hand, most of the metals are active and combine with air, moisture, carbon dioxide and non-metals like oxygen, sulphur, halogens, etc. to form their compounds, like oxides, sulphides, carbonates, halides and silicates. i.e., they occur in nature in a combined state. A naturally occurring material in which a metal or its compound occurs is called a mineral. A mineral from which a metal can be extracted economically is called an ore. An ore is that mineral in which a metal is present in appreciable quantities and from which the metal can be extracted economically
In the earth’s crust, sulphur and silicon are found in large quantities. Sea-water contains large quantities of chloride ions (obtained from dissolved sodium chloride). Most avtive metals are highly electropositive and therefore exist as ions. It is for this reason that most of the important ores of these metals occur as (i) oxides (ii) sulphides (iii) carbonates (iv) halides and (v) silicates. Some sulphide ores undergo oxidation by air to form sulphates.This explains the occurrence of sulphate ores. Ores are invariably found in nature in contact with rocky materials.
Materials Found in India:
These rocky or earthy impurities accompanying the ores are termed as gangue or matrix. Iron Iron ore reserves in the country are estimated at 1750 crore tonnes. Major iron ore mining is done in Goa, Madhya Pradesh, Bihar, Karnataka, Orissa and Maharashtra.
Occurrence of Metals Video
Useful for CBSE, ICSE, NCERT & International Students
Grade : 8
Subject : Chemistry
Lesson : Metals and Non Metals
Topic: Occurrence of Metals Video
Visit www.oztern.com to find personalized test preparation solutions for Pre Medical – AIPMT, AIIMS, JIPMER, State, Pre Engineering – IIT JEE, JEE MAIN, BITSAT, State and Foundations – Class 6 to 10.